Clear Solar Power Crookes Radiometer Sun Light Energy Glass Windmill Spinning Vanes

So this floats freely and spins without any noticeable resistance, I'd say approches 300-500 RPM in bright daylight. Will lollygag in slight sun, but it needs quite a bit to get rotating. Its totally cool and what I expected, works as expected. Crystal clear. I see nothing wrong here. Buy one for the kids, it will open thier eyes to "thats JUST THE SUN" no moving parts, nothing complex, just very simple visually perception of...well you tell your kids what you want, but it ain't gonna stopt this from spinning. I understand it, but its still satisfying.

I purchase these raidometers as gifts. Before issuing them i test them for rate of spin. I have a very good working model and that is the base sample for rate of spin from a given level of light. I recently received a unit that did not meet standard and will return it. In all, I must have bought at least 15 of these units and only two were returned. In bright sunlight they should spin like crazy. If they are making 60 RPM in brught sunllight I consider that poor quality control. I will continue to purchase these units because they are well built but maybe it is the level of vacuum or the one point bearing and excessive resistnce that is at fault. Overall I do like this unit but will not hesitate to return a poorly performing unit. Update: The unit that works ell spins clockwise when viewed from the top. The recent purchase units that were returned are spinning counter clockwise. The construction is good but minor flaws are acceptable. It is the rate of spin that is the issue. If they spin slowly, or not at all, I return for replacement. Slow is 60 RPM or less in direct sunlight. The unit that works well must be spinning aboout 200 RPM, maybe 300. One looks sick and the other is performing at the Olympicc level.

Sweet little radiometer but purchase an extra. One of my three I ordered did not work upon arrival.

The radiometer initially worked fine. However, after about 5 months it no longer spins in direct sun. It will begin to spin when the sun comes out, but it then slows and stops like something is preventing it from spinning. I had an older radiometer from another company for over 20 years in the same spot without an issue.

Product ordered for Christmas and arrived broken. The arms holding the black squares arrived broken and stop it from spinning. I noticed too late and cannot return now.

I use this as a display for solar and people love looking at it and seeing it spin.

Está perfecto! Like I always dreamed in my science classes in high school

Good science project that reminds me of when I was in 4th Grade. The movement is smooth and looks mostly good. There are some small imperfections on the vanes. It functions well in the light and is inexpensive for the result.

great science toy now i have one

A really amazing piece of decor, works like a charm, I am really interested in this, Great idea.

曇り空の日光だけでこんなに回ってます。 正直ラジオメーターってもっとのんびりしたものかと思ってたのでびっくりしました。 お部屋の彩としてとっても素敵ですよ！

I put this in my office in a window sill. It's a neat product to see it spin when it starts to get sunny out.

Product same as advertised